Recently, semiconductor devices such as flash memories or the like tend to be highly integrated, and patterns have been remarkably miniaturized according to the high integration trend. When forming these patterns, a process of performing a certain process such as a nitriding or an oxidizing treatment on a substrate is often carried out as one of manufacturing processes.
As one method of forming such patterns, there is a process of forming a groove between circuits and forming a liner film or a wiring on its surface. This groove is configured to have a high aspect ratio according to the recent miniaturization trend.
When a liner film or the like is formed, it is required to form a film having the good step coverage without a variation in film thickness even on an upper side surface, a middle side surface, a lower side surface, and a bottom portion of the groove. By forming the film having the good step coverage, it is possible to make the characteristics of a semiconductor device uniform between the grooves, thereby suppressing a variation in characteristics of the semiconductor device.
In order to process such groove having a high aspect ratio, an attempt has been made to process the groove by using a heated gas or plasmized gas, but it was difficult to form a film having the good step coverage.